When is the first measureable snowfall for the Red River Valley and Lakes Region? With the threat for significant snows across the Valley and Lakes Region this weekend, the question about early season snowfalls has been raised. Based on the climatological record available measureable snow is not at all uncommon in early October. Typically snow that falls this early in the season melts off and may even be followed by a period of much milder weather.
Notable early season snows include the October 2 1950 snowstorm and The October 7 and 8 snowstorm of 1985.
Below is a table of the earliest one inch observed snow fall based on the 1940 to 2010 period of record. While this is not a comprehensive list it is designed to give an idea as to when the earliest 1 inch of snow has fallen. Due to the variability of weather at any given location, the first inch of snow can be more than two months later. The average first inch snowfall is based on the 1981 to 2010 climatology.
NORTH DAKOTA SNOW/YR AVG 1IN MINNESOTA SNOW/YR AVG 1IN
CAVALIER 7NW SEP 26/1972 NOV 3 AGASSIZ WLR OCT 14/1959 NOV 7
EDMORE 1NW SEP 26/1972 OCT 30 BAUDETTE SEP 26/1941 NOV 1
FARGO HECTOR FLD OCT 2/1950 NOV 11 CROOKSTON OCT 5/1974 NOV 11
FORMAN 5SW OCT 2/1950 NOV 16 DETROIT LAKES SEP 26/1942 NOV 10
GRAND FORKS NWS OCT 2/1950 NOV 15 FERGUS FALLS OCT 9/1970 NOV 15**
HANSBORO 4NNE SEP 11/1989 OCT 27 OTTERTAIL OCT 2/1950 NOV 7
LEEDS SEP 22/1995 NOV 3** RED LAKE FALLS OCT 1/1974 NOV 8
LISBON SEP 22/1942 NOV 13 THORHULT OCT 2/1950 OCT 31
PETERSBURG OCT 2/1950 OCT 28 WADENA 3S SEP 25/1942 NOV 11
VALLEY CITY 3NNW OCT 2/1950 NOV 14 ITASCA ST PK OCT 7/1970 NOV 9
**Please note that some stations had a few missing years of data.
Looking at the above table it is apparent that the first inch of snow in the northern plains can occur quite early. Trace snow amounts have been noted earlier than the dates listed above. Also, there is no correlation between early season snowfalls and overall winter precipitation. In fact, several of the winter seasons with early accumulating snows ended up with below normal seasonal snowfall totals.